Telephone-transmitter.



No, 817,140n PATENTE) APR. 3, 1906 W, W'. DEML TELEPHONE TRANSMITTER,

yAPLIUATIQN' FILED AYE. 3, 1902.`

l UNITED' STATES PATENT OFFICE. WILLIAM w.' DEAN, OF CHICAGO, ILLINOIS, AssIoNoR rOlKELLOGG I swIroHPoAen-AND sUPPLY COMPANY, or CHICAGO, ILLINOIS, A

CORPORATION or ILLINOIS.

. TELEPHONE-TRANSMITTER.

Specification of Letters. Patent.

vPatented April 3, 1906.

riginal application led January 27, A19112, Serial No. 91,1156. Divided and this application filed April 8, 1902. Serial No. lOl-|149.

To all whom tmc/,y concern:

Be it known that l, WILLIAM W, DEAN, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented a certain new and useful Improvement 'in Telephone-Trans mitters, (Case No. 59,) of which the following is a specification.

My invention relates to telephone-trans mitters of the type employing comminuted conducting material as a resistance-varying medium interposed between two electrodes Vwhich are adapted to partake of relative movement.

In my Patent No. 687,499, dated November 26, 1901, I have shown,v described, and generically claimed one species of my invention inl which the-diapln'agm is laterally o'U set and the chamber of the comminuted material is located in suoli offset portion.

. The subject-matter Oi my present applicaftion forms'a diiierent species oi the same gelne'ric invention illustrated in said patent and embodies, a structure in which the chamber for the resistance-varyin medium is located in a 4separate cup carrie by the diaphragm.

A supplemental flexible diaphragm, ring, or

fiexible wall servesto close the cup, and suitable electrodes associated with said cup and sup lernentalV diaphragm are provided within t e .chambeigthe back electrode, which is associated with fsaid supplemental diaphl'agm, being preferably provided with rigidabutment or support. I

In the. accompanying drawings, forming a part of 'this specification, in which the same reference vcharacters designate like parts throughout, Figure 1 is a sectional view of the transmitter embodying the invention. Fig. 2 is a view of the detached parts thereof. Fi 3 is a back view of the same, and Fig. 4 is a detailed view.

A support or'if'ront ieee 2, of any desired torm,carriesthe'usua mouthfpicce 3 and is itself supported bythe inelosing Casing 4. The main diaphragm -5 is provided upon the periphery with the usual packing-ring 6, ot' rubberor similar material, and is adapted to e be yielding-ly pressed against the face or supdiaphragm.

' their outer ends being securedv to the raised rib 10 upon the back face of the-front plate 2 by means of suitable screws y11. p hand spring 7 (shown in Fig. 3) bears upon the diaphragm 5 away from the packing and serves to dampen the vibration of the lhe cup or receptacle forming. the chamber of the comminuted material, which is preferably granular carbon, is composed of a hard-rubber ring 12, secured to lthe rear face ofi the diaphragm 5 by means of suitable screws 13, passing' throuv h the diaphragm and threadin into the ege of the ring 12.

The left- As many of t ese screws as are Anecessary or desirable may be employed. The 4Jfront electrode comprises. a carbon disk 14, secured to a metal plate 15, preferabl by electroplating the face of the carbon disk and then soldering the same to the plate 15. This plate is into the edge of the ring.. vThis sup lemen` tal diaphragm is made of thin exib e sheet metal, but of course may be formed of other suitable material, such. as mica. The back electrode is likewise formed of a carbon plate 01 disk 20, secured to the face of, the metal disk 2]., provided with a central shank 22, upon which is first threaded a nut 23. The shank is then extended through a central aperture in the supplemental diaphragm 18 and is threaded into a metal block 24. The block 24E secures the electrode firmly in the supplemental diaphragm and projects through an aperture in a second block 25, hired in the rearwardly-deflected Ortion 26 of the bridge strip 27 which exten s across the back of the front piece of the transmitter and is secured atits'ends to the raised rim 10 thereof by means of screws 28. The block 25 is secured in the portion 26 of the bridge-strip by means of its shank, which is upset at one. or more points near the periphery of inner end, as

IOC

.shown at 29, to secure it iirmly in-place. This may readily be accomplished with a prick-punch or in any other desired way. The set-'screw 30 is threaded into the block 25 and serves to secure the block 24 in' adjusted position in the block 25. The back electrode is thus adjustably secured and rigidly supported and has a piston-like move'- ment relative to said chamber.

A binding-post 31 is mounted upon an insulating-block 32, secured in any desired way to the upper end of the bridge-piece 27, as shown in Fig. 3. the insulating-block 32 and through one side of the binding-post 31 to secure the latter in position 4and to bind the end of the circuit wire or conductor within the same.. minal strip 34 is connected with binding-post 31 in an adjustable manner, and a light wire 35 extends therefromto a clip 36, Fig. 4, secured to the diaphragm by means of a suitable screw. The circuit or" the transmitter will therefore extend from the bindin -post 31, through the clip 34, conductor 35, c ip 36, di a hragm 5, front electrode 14, the granular carbon which'is contained in the'chamber formed bythe ring and between the two electrodes, thence through the rear electrode, the metalv ieces 24 and 25 to the bridge 27. From t ,oint the circuit may be completed through t e metallic cup 4 and the trans vmitter-wire, or a second conductor` may. beA secured to the bridge- 27, and lead out thej point desired.

In the operation of the devicethe soundwaves impingethe: dia hragm 5 and set the same into vibration, w ereby the. front electrode is caused'toapproach and recede from the rear electrode,- and thus causes a varying pressure upon the' granular carbon, which induces a correspondinggvariation of the cur rent in the transmitter-circuit. One advantage of locating the chamber on the diaphragm is that the granular carbon is continually disturbed, and is thus kept in a more sensitive condition than where' the chamber is mounted in a stationary manner.

' It is apparent that various modifications may be made in the details of lconstruction without departing from the spirit or scope of. my inventiomand I therefore do not Wish to' be limited to the precise details shown; but, Having'described-my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A telephone-transmitter comprising a y' iiat main diaphragm, a ring secured .to the diaphragm secured to the back o 6o 'back of said main diaphragm, a su plemental said ring, sai ring constituting a medium of non-yielding connection between the two diaphragme, .a solid backing and non-yieldin connection between said back and the midd e portion of said sl pplemental diaphragm, frontand back 'electrode-surfaces within the chamber pro- A screw 33 passes through The terf 'phragm secured to the vided between the two diaphragms, the front electrode-surface being. movable withV theV i main diaphragm, andthe back electrode-sur face bein stationary and rigidly connected with said acking, and granular carbon inter'- posed between said electrode-surfaces, substantially as described.

2. In a telephone-transmitter, the combination of a body or casing, a flat main diaphragm, a ring secured to the back of said main diaphragm, a supplemental diaphragm, suit-` able means for securing said supplemental diaphragm to the back of said ring, said ring constituting a medium oi non-yielding connection between the two diaphragms, front and back carbon blocks securedcrespectively to the main andsupplemental diaphragms,

anular carbon interposed between said car.

on blocks, a bridge back of all said diaphragms, and non-yielding connection between said bridge and said supplemental diaphragm, the front carbon block being vibratory with the main diaphragm, and .the said back carbon block being stationary or rigid with the said bridge, substantially as described:

3. Ina telephone-transmitter, the combination cfa body or casing, a flat main diaphragm, a ring secured to the back of said diaphragm, a carbon block secured to saidl main diaphragm, a supplemental mica dia# said ring constituting a medium of non-yieldackf'of said ring, the

ing connection between the' two daphragms,

a carbon block secured to said supplemental diaphragm, granular carbon interposed between the two carbon blocks, a bridge, and a looF non-yielding connection between said bridge ,l

and saidlsupplemental diaphragm, said rstmentioned carbon block being vibratory with the main diaphragm, and said last-mentioned carbon block being stationary or rigid with the said bridge, substantially asvdescribed.

4. A telephone-transmitter comprisin a flat main diaphragm, an open non-fleXi le ring, a-ileXible auxiliary diaphragm, suitable l means for securing the auxiliary diaphragm to one side of'the ring to form a cup, the au .iliary diaphragm formin the bottom of the cup, op ositely-arrange electrodessecured to said iaphragms wlthin the cup, granular carbon between the'two electrodes, means for securing the main diaphragm to the said cup, and abridge rigidly connected with the electrode associated with Athejainriliary diaphra m, substantially as described.

5. n a telephone-transmitter, the combination of a suitable body or casing, a flat main diaphragm suitably secured to said cas-y ing, a hollow member having its open end projecting from the back of said diaphragm, said hollow member being rigid with the diaphragm, a supplemental diaphragm having its marginal portion secured around the perimeter of said member, the said member coni, etituting medium of non-yielding connection' timed a between said bridge and the finiddle portion of said supplemental diaphragm, the front electrode beingrigidlyooneoted to and vibratory With the main diaphragm, and the back electrode being' stationary or rigid with said bridge.

Signed by lne at hiGagO, county of Cook, State of illinois, this 1st day of A ril, 1902. WILLIAM DEAIIa between' the two diaphragme, front and back electrodes, Within the Chamber provided by said member and supplemental diaphragm, the central portion of Said main diaphragm constituting the front Vy/ iall of s'ad chamber, I and the suV plemental diaphragm the rear Wal-1 thereoi both electrodes being thereby l adapted to have some movement or Vibration relative to the said hollowrnelnberh anular Witnesses: s i' carbon between Said electrodes, a bri( ge back JOHN CROSBY NEELY, ROBERT LEWIS AMES.,

of'eaid diaphragm; anorbyielding connectionl 

